Pay station circuits for automatic telephone systems



Jan. 29, 1952. c. E. LOMAX ETAL PAY STATION cmcurrs FOR AUTOMATIC TELEPHONE SYSTEMS Filed Feb. 5, 1948 G2 a. N2 0 o o: 3 m pmwmum i $5555 232; cow l 86 X "#28228 36 .5975 Q8 02 5 8% 35 A H MQQ mmw .8 83 Q m 11v m 69 m 3 & 8 N90 3 N, S w [o -36 mm E m u :06 23 8m 0a m 0 I 02 M2: a m 58 WW x b4 QNI M 56 INVENTORS Clarence E. Lomux John M. Wild Patented Jan. 29, 1952 PAY STATION CIRCUTTS FOR AUTOMATIC TELEPHONE SYSTEMS Clarence E. Lomax, Chicago, Ill., and John M. Wild, Ithaca, N. Y., assignors to Automatic Electric Laboratories, Inc., Chicago, 111., a corporation of Delaware Application February 3, 1948, Serial No. 5,954

18 Claims. (Cl. 179-63) The present invention relates to automatic telephone systems, and more particularly to paystation circuits for such systems.

Heretofore in automatic telephone systems, it has been the established practice to render to paystations free incoming calls and to make charges against paystations only for completed outgoing calls. This practice has led to certain abuses by some persons using the paystations that are highly objectionable from the standpoint of.

the operating telephone company. For example, it has been found that a person at a paystation will initiate and extend a call to an ordinary subscriber substation, hold the call until the ringer at the subscriber substation operates a fixed number of times, and then disconnect obtaining a refund of the coin deposited at the paystation. By prearrangement, the subscriber at the subscriber substation will not answer any call immediately, and when operation of the ringer thereat takes place the fixed number of times and is then arrested, he is signalled that the person is at the paystation. The subscriber at the subscriber substation then initiates and extends a call to the paystation; whereupon the person at the paystation answers the call completing a connection.

The fundamental complaint of the telephone operating company against this practice is not the loss of revenue at the paystation, although this may be substantial, but is the unnecessary and excessive use and consequent busying of the automatic switching apparatus incident to carrying out this practice.

Accordingly, it is a general object of the present invention to provide in a telephone system, a substation circuit that requires a call registering operation in order to answer an incoming call thereto.

Another object of the invention is to provide in a paystation circuit, outgoing call registering mechanism and incoming call registering mechanism.

A further object of the invention is to provide in a paystation circuit coin controlled call registering mechanism for selectively governing the completion of free calls and of first and second types of charged calls respectively requiring corresponding first and second charges.

A still further object of the invention is to prothe particular arrangement of the circuit ele- 2 ments of the system; whereby the above outlined and additional operating features thereof are attained.

The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying drawing, in which the single figure illustrates the details of an automatic telephone system having incorporated therein the features of the present invention.

Referring now more particularly to the drawins, there is illustrated an automatic telephone system comprising an exchange serving a plurality of paystations, including the paystation I0, a plurality of ordinary subscriber substations, including the ordinary subscriber substation I20, and a plurality of special substations, including the special substation I30. The special substations I30, etc., are arranged at fire stations, police stations, and at other such locations. The paystations I0, etc., are provided with telephone lines I00, etc., extending thereto having conventional line circuits IIU, etc., individual thereto; the ordinary subscribersubstations I20, etc., are provided with subscriber lines I2I, etc., extending thereto having conventional line circuits I22, etc., individual thereto; and. the special substations I30, etc., are provided with telephone lines I3I, etc., extending thereto having conventional line circuits I32, etc., individual thereto. exchange comprises a plurality of finder-selector links, including the link I80, as well as a conventional distributor I10, commonly associated with the links I80, etc., and with the line circuits IIO, I22, I32, etc. Also the exchange comprises a group of suburban selectors, including the suburban selector I50; preferably, the suburban selectors I50, etc., are of the conventional Strowger type having access to trunk lines, not shown. extending between the exchange illustrated and other exchanges, not shown. Further the exchange comprises a group of ordinary connectors, including the ordinary connector 200, and a group of special connectors, including the special connector I60. Finally, the exchange comprises an operator position IEO having a group of trunks, including the trunk MI, extending thereto and terminated by conventional trunk circuits I42, etc., individual thereto.

Preferably, the finders of the links I 80, etc., are of the conventional Strowger type having access tothe telephone lines I00, etc., to the subscriber lines I2I, etc., and to the telephone lines I3I,

Also the r 3 etc. Also the selectors of thelinks I80, etc, are of the conventional eleven level Strowger type having access to the trunks I51, etc., extending to the suburban selectors I50, etc., in the eleventh levels thereof; having access to the trunks Ml, etc., extending'to the operator position Milin the tenth levels thereof; having access to the trunks I61, etc., extending to the special connectors I60, etc;, in the ninth levels thereof; and having access to the trunks .219, etc, extending to the ordinary connectors 200; 'et'cg-inthe eighth levels thereof.

Preferably, the special connectors 14.556, etc, are of the conventional Strowgertypewexcept that they are not operative to "reverse the polarity-1 over the calling line extending thereto when the call is answered on the calledline e tending therefrom. Further the special connectors 46%, etc., have access to the telephone lines 31, etc., extending to the specialfsubstations I39, etc.

Preferably; the ordinary .iconnecto'rs are identical to the connector 230 which is ,of the conventional Strowger type except that it incorsrate anadditional or unlock relay in there- "l'ay group. Specif cally, in the connector 258, "the relay 'group comj-pri'ses a back-bridge relay R228, a line relay R230, a hold relay R248, a ring 7 cut-oft relay R250, other conventional relays not she's/n, as 'wellas the additionalor unlock relay R256; together-with the 'Strowger mechanism NW-providedwiththre individual wipers indicated. Ihe Strowger mechanism Zlll has access "to the subscriber "lines 12!, etc extencling to the ordinary subscriber substations I26, etc., and

tothe telephonelines I00, etcextending to the from a consideration of the extension of various calls involving the paystation It, the ordinary subscriber substation 120 and the special substation l3ll. 7

First assuming that a call is to be extended from the calling paystation IE! to the called special substation [30, theperson at thepaystation it initiates the call by removing the receiver .83 from the switchhook ll; whereby the switch- Each of theordinary subscriber substations I20, etc, and-leachlof the special substations me, etc, is provided with conventionalisubstation apparatus 'includin'g 'a transmitter, a receiver, a

dialof the 1 l-point.type,as well'as a.ringer. :For

example, each or the ll point 'dials at the varioussubstations maybe of thecharacter of. that disclosedinUyS. PatentNo. 2,013,171,.granted on Septeinber 3, l93'5, to Edward S.- Peterson;

EreferahLy,-eachof-the ipaystations is identical .to'thepayst'ation [B that comprises a transmit- .ter: 82, a dial 'ili of the ll' point type, a switchhook H- controlling a hook switch 29, and a control networh including two asymmetrical currentponducting devices in the form ofcopp'er 'oxide rectifierstifl and 8|, a glow tube il'L'a lock relay-R50,-and1inlock relay R68 and-a collect relay'Rimnlso the paystation Ii] comprises coin receiving, collecting and refund mechanism, includinga local call chute adapted to receive a five-cent piece or equivalent slug, either being,

referred tofas a coin, a suburban call chute l2 a'dapted'to receive a ten-cent pieceor an equivalent slug, either being referred to as a'c'oin, an answer'chute 15 adapted to receive" a five-cent *pieceorail-equivalent slug, either being referred "toasa coin, and extending to a collect loox not shown, "and acollect chute [3 extending to a colextending to a refund reception, not shown. Finally, 'the pa'ystation i 0 comprises a meter t! associated with a push button '10 that is pro} vided' with-akey controlled lock mechanism 11% and which cooperates with the'answer chute IE as explained more fully hereinafter.

' A better understanding or theconneeabnand arrangement of the apparatus disposed at the p'aystationilll in eenjuricuen with the spa-ant access thereto.

hook if! is pivoted in the clockwise direction upon the mounting blo'ck 18 causing the push rod is to rise-and disengage the horizontal arm of the pivotally mounted bell-crank 3!. When the hellr'crank'3'l is thus disengaged, the coil spring 33 slides the rod 32 towards the right; whereby the arm 36 pivoted ina clockwise direction causing the g $e35 to close the refund chute i l. "Atthistiiriethe gate 35 closing the refund chute I4 cooperates with the gate 3'! closing the collect chute l3 in order to provide a pocket for trapping a, deposited coin. Also the switchhook winding of the line rlay therein to the p: itive line conductor cm: of thetelephone line i the negative line conductor Cllll being connected via the fimpulsefcon'tacts 'ifi'of the dial iafthe asymmetrical current conducting device Bilfthe eontactsrzatne transrriittenm, the, receive 23, and the' contacts 52 to the positive'line con ,u'ctor c102, Accordin'glv'the line relay iriithe line circuit Ht operates in order toinit'iate operaticn of thedistribiitor I10 over the sta'rt conductor CIH; whereby fthe distributor ll ilflas- "signs an idle one of the finder-selector links, such for example, as thejlinkjl8ll, foruse at this time. The finderjof the linkIBIl' operates to find the 'ca llingtelephoneline It ll, the telephone line it!) "being marked as callingin the linecircuit He by the application oif battery potential upon the "control conductor cl 04 thereof. When the finder or the link 'rae finds the calling telephone line lee, ground potential therein is applied to the control wiper thereof and consequently to'the control conductor (JIM of the telephone'line lflil; whereby the cut-off relay, not'shown, in the line circuit l H] operates in 'ordertoepply ground'pm 'tential to the control conductor CW3 of the telephone line J00 marking the telephoneline Iilil as busy to'-'the connectors 211E), etc.,having Also upon operating the cut-off relay in theline circuit 1 It! cuts off the linerelay therein completing a direct loop circuit between the calling paystation Iii andtheline reiay'in the selector ofthe link I;"wherebydial'jtone in the selectoroi the link lall is returned over the loop circuit "indicating to the person at h the calling paystation l I! that he-may proceed to dial the digits comprising-the directory number ot the called special substation l30. The person at the calling paystationlil pin ceeds to dial the directory'number or the called special substation 130, without depositing a coin in'the' local call chute I I, since calls from the call "-ing paystation ID to the called special substation I 30are free.- The directory numberot the'call'd crating the finger wheel of the dial in accordance therewith; whereby the finger wheel, upon its return, operates in a corresponding manner the impulse contacts 16, causing a corresponding series of impulses, constituting the digit, to be transmitted over the loop circuit including the telephone line I00. More particularly, the impulses of the first digit 9 are transmitted from the impulse contacts 16 via the path including the asymmetrical current conducting device .80, the contacts 29, the transmitter 02, the receiver 83. and the contacts 52 across the line conductors CI 0| and CI02 of the telephone line I00. In order to prevent the transmission of impulses over the line conductors CIOI and CI02 of the telephone line I00 from having a tendency to operate the lock relay R50 included in series with the ringer 80 and the condenser 85, also bridged across the line conductors CIOI and CI02 of the telephone line I00, the last-mentioned circuit also includes the glow tube 01. Specifically, the glow tube .01 will not be rendered conductive during the trans mission of the digit thereby positively preventing a false operation of the lock relay R50 and the ringer 80 included in series circuit relation in the ringer circuit bridged across the line conductors CIOI and CI02 of the telephone line I00.

When the first digit 9 is dialed, the selector of the link I80 responds thereto to select the group of special connectors, including the special connector I60, and then to select an idle special C011".- nector in the group mentioned. For example, the selector of the link I80 may select the trunk Itl extending to the special connector I50. At this time the selector of the link I80 switches through extending the loop circuit to the line relay in the special connector I60. The special connector I00 then responds to thesecond and third digits 0 and 0 to select the telephone line I3I extending to the special substation I; whereby the idle or busy condition of the telephone line I3I as marked by the associated line circuit I32 is tested by the special connector I00 in accordance with conventional practice. In the event the special substation I30, is busy at this time, the special connector I50 operates to return busy tone current over the loop circuit extending back to the calling paystation I0; whereby the person thereat disconnects by replacing the receiver 83 upon the associatedswitchhook I'I bringing about the release of the apparatus in a manner substantially identical to that described hereinafter.

On the other hand, in the event the special substation I30 is idle at this time, the special connector I60 operates to project ringing current over the telephone line I3I in order to operate the ringer at the called special substation I30 and to return ring-back tone current over the loop circuit to the calling paystation I0 indicating to the person thereat that the called special subsation I30 is being signalled at this time. the person at the called special substation I30 answers the call, the special connector I60 switches through to complete a connection between the calling paystation I0 and the called special substation I30; however, the special con-x station I0, since such operation would block theestablished connection in an undesirable man ner. Accordingly, the person at the calling paystation I 0 converses with the person at the called special substation I30, the connection beingiree as previously. noted.

.. At the eonclusionof; the established connection;

ill

when theperson. at the calling paystation I0 disconnects by. returning the. receiver 03 upon the associated switchhook II, the switchhook I1 is pivoted. in the counterclockwise direction about the mounting block I8 depressing the push rod It to re-engage the horizontal arm of the pivotally mounted bell-crank 3|. When the bell-crank 3| is thus engaged, it is pivoted in the clockwise direction sliding the rod 32 against the: bias of the coil spring 33 toward the left; whereby the arm 30 is pivoted in the counterclockwise direction causing the gate 35 to open the refund chute I4. Alsothe switchhook I'I opens the contacts 29 interrupting the loop circuit extending between the paystation I0 and the special connector I60; whereupon the special connector I00 is released bringing about the release of the link I80. When the link I80 is thus released, the line circuit IIO again operates in order to return battery potential upon the control conductor CI03 of the telephone line I00 marking the telephone line I00 as idle to the connectors 200, etc., having access When thereto. Also at this time the line circuit I32 is operated to mark the telephone line I3I as idle to the special connectors I60, etc., having access thereto, assuming that the person at the special substation I30 has disconnected. At this time the established connection between the calling paystation I0 and the called special substation I30 is released and all of the apparatus involved therein is completely released and available for further use.

Now assuming that a call is to be extended from the calling paystation I0 to the called ordinary subscriber substation I20, the person at the paystation I0 initiates the call by removing the receiver 83 from the switchhook I'I; whereby the line circuit I I0 is again controlled to govern operation of the distributor I10; whereby the link E may be again assigned for use. The finder of the link I80 again operates to find the telephone line I00 extending to the calling paystation !0; whereby dial tone current in the selector of the link I80 is returned over the loop circuit to the calling paystation I0; all in the manner previously explained. In order to complete a connection from the calling paystation iii to the called ordinary subscriber substation I 20, it is necessary for the person at the calling paystation I0 to deposit a coin in the local call chute II, as well as to dial the directory number of the called ordinary subscriber substation I20, which directory number may be 800. However, the person at the calling paystation I0 may attempt the extension of the connection in an unauthorized manner to the called ordinary subscriber substation I20, without depositing the coin in the local call chute II, merely by dialing the directory number 800 of the called ordinary subscriber substation I20; whereupon the apparatus is released as explained more fully below.

First assume that the person at the calling paystation It attempts the extension of the connection therefrom to the called ordinary subscriber substation I20 inan unauthorized manner by failing to deposit a coin in the local call chuteII and merely by dialing the directory number 800 ,.When the firstdigit 8 is dialed the selector oi'the link I30 responds thereto to select the group of connectors, including the connector 200, and then an idle connector in the group mentioned: For example.- the selector of the linkxl=80 mayzselect: the. trunk 2 I 0 extending to thaeonne tnr 20mm trunk 2I.0..being markcdas 7 idle to the sel'ector of the l'i'nk 'IPBNbythaapplication of battery potential upon the controliiconductor C2 l3 thereof via a path, no shown. When the selector of the link'l'80' operates to select the connector 28B viafthe trunk 21!]; iti'switches through completingv a direct loop circuit from the cal-ling substation. l to the line-relay R230 in the connector 200 which loopcircuit inoludes: the contacts'2-22 and.224,-aswell asthezline conductors CZ-H and C212 ot thetrrunkim'. 'Whn this loop circuit is'completed, the-linerelay -Rflfl operates tocomplete, attthe contacts; 23 Ita circuit-for operating theihold telayRZ'dB; and-to complete a circuit; not 1 Shawn for. zoperating 'the transfer relay, not-shown, in the connector'zlill; Theli'ne relay R230- ih" the-connectorWo -then follows the second digit (1-. Each time line relay R230 restores andthen re'operates; its interrupts and then reco'mpleteaat the contacts.

231 the circuit for retaining operated theshol d' relay R255 the latter relay being of theslow-tbrelease type, remaining-operated during impuls ing. 7

Also each time the line-relay RZBe'reStQres and' then 'recperates, it completes and then"- interrupts, at the contacts 232', a path, including the 7 a the dialing conductor-C24hfor tlierotary'magnet,

not shown; of" the strowger mechanism 210.

Whenthe thirddigitll is then dialed; the: line relay Rifiiragain follows repeating, at the "contacts 232, over the'dialconductor C243 and'the circuit, not shown; to the rotary 'magnet'; not shown, of thestrowger mechanism 2 16i At the conclusion of'the" third digit/0; thetestrelay; not? shown, tests the idle or busy" condition of" the subscriber iine'iZl extending to the called ordinary subscriber substation I20 that has" been selected at this time; whichsubscriber line Hl' ismarkedeither as-idle or busy'bythe associatedline circuit 122; Inthe event the'subscriberline l2 5 is busy at this'time, thetest'relay; not shown, operates'in order to bring aboutthe returnof V 'busy'tonecurrent'over-a' path,'not shown, to the loop circuit extending back to the callingzipay station It in order to indicate to the person thereat that the desired-connection'maymotbe had due to the busy condition-mentioned; The person at the calling paystation-ll! then discon-V nects efiecting the release of the apparatus in; a manner substantially identical tothat previously explained. 7

New assuming-"that the; subscriber line I 21 ex tending to the'calle'd ordinarysubscribersubstation i26 isidleat'thls'time, the test relay; not

shown, does not operate'and-a switch relay; not 7 shown; operates to 1 complete a circuit including the ring-ing-conductorczili, the upper'windingof the ringout-off relay-Bibi), th8C01ita0T/S125 L154 7 and 26 i 2'53 for projecting ringing current" overtheline conductors ofathe subscriber line I-Zl in orderz'torioperate theiringer*atithev-called: ordinarysubscriber substationasl20; an'd t'or returnrring person thereat. that the called: ordinary sublscriber substation f2llisbeing: signalled at this time. V

When the subscribera-t-the called: ordinary subscriber substation =|2=fl answers. the call .a-ilow resistance circuit-substantially identical to that 7 previously traced is completed for energizing the upper winding of the ring out-offv relay' R250; wherebythe latter relay operates.- to-complete at holding circuit, not shown} for. energizing; the: lower winding thereof; to interrupt; at thereon tactsx25l and 25%, the. circuit for projecting ring.- ing current over the subscriberfline: I2 to interrupt the path not shownr forv returning'i'ring back. tone. current over the'loop circuitextending back to: the calling paystation 'l'0 ;and to complete, at the contacts 252 and 253, a loop cir cuit; including the contacts 2M and 26%,between the: called ordinary subscriber substation l20 andv the'upper and lower win'dingsflof the backbridge-relay R226. The back-bridgerehy-RZZB then operates to reverse, at the contacts 22!, 222-,

223 and 22 i, the polarity of the trunk 210 with respect to the upper and lower windings-of the line relayRZSfi; whereby'the polarity of the loop circuit extending back to thecalling pay-station ill is reversed, ground potential being applied to neline conductor C'i-illandbat'terypotentialbeing applied to the line conductor 0602 When the polarity of the loop circuitincluding the line.

conductors Cit? and CliiZ is thus reversed, the:

asymmetrical current conducting: device 89' blocks the passage of" current therethroug-h via the previously traced. path, including the impulsiing contacts it or the dial- 75, the contacts 2 9} the transmitter-'82, thereceiver 83gand the c'o'n Accordingly, the loop circuit extendingfrom the calling paystation l tto the linerelay1R2 5o in the connector zil'fl-iseffectively interrhpted by the asymmetrical current conduct; ing; device 85 bringing about the restoration of the linerelay arse; Upon restoringthe line relay"155235--interrupts at the-oontacts-HL'the citcuit for energizing the winding ofth'e"hold'- relay R240 in order to cause the latter'relaytorestore shortly thereafter, it being of the show -to -release' type; Upon restoring the hold' relay Ri -llfl-brihgs about the release or the Strowger mechanism -2 10 and the remainder eithe -operated relays in the connector 2%; wherebybattery potential" is returned upon the control conductor C2 I 3 of the trunk'l'lil again marking the trunk 260 andcon sequently the connector z flll-as idle; to *the selec tors of the links est; eta, havingaccesss'there to. Also the link 588 isreleased; whereby: the line circuit lItis reoperatedlinorder to'lock'out' V of servicethe telephone line I 06 and the calling paystationlil. At this: time the person at the" calling 'paystation I it can place the telephone; line I00 back in" service again only'by" disconnecting in: themanner previously explained. 01? course;

the subscriber at the called ordinary' subscriber substation i28 upon" answering: the: call" thereto: found that the call" had' ben abandoned and then. disconnects. Accordingly; in theevent a person at the calling paystation 10 attempts-- to extend a. call to the called ordinary "subscriber. substation I26 in an unauthorized mahner by failing toideposit 'a coin in: the :1oca'lcall chute' I I and merely by dialing the directory 'number; 800. of the called ordinary subscriber?substation lim theaf'switchingi'apparatus 'is goperatew'to eirtend the call and is then automatically released when the subscriber at the called ordinary subscriber substation I answers the call; and then the paystation I0 is locked out of service by the associated line circuit IIO until the person thereat disconnects by replacing the receiver 83 upon the associated switchhook I'I; all in the manner described above.

Now assuming that the person at the calling paystation I0 after initiating the call by moving the receiver 83 from the associated switchhook I'I first deposits a coin in the local call "chute II before dialing the directory number 800 of the called ordinary subscriber substation I20. When the coin is deposited in the local call chute I I, it falls past the end of the lever engagingand pivoting it against the bias of the coil spring 2'! in the counterclockwise direction; whereby the latch 29 carried on the lever 25 disengages the associated spring permitting closure of the contacts 88; whereby a multiple path including the asymmetrical current conducting device 8|, the winding of the collect relay R90, the contacts 88 and 29, the transmitter 82, the receiver 83 and the contacts 52, is completed between the line conductors CIOI and CI02 of the telephone line I 00. Although this multiple path is completed, no current passes therethrough since the asymmetrical current conducting device 8| effectively blocks the path since the line conductors CIOI and CI02 of the telephone line I 00 are respec tively poled negative and positive at this time. Thus the collect relay R90 is not operated and current in the loop circuit between the line conductors CHM and CI02 of the telephone line I00 passes via the first mentioned path, including the asymmetrical current conducting device 80. The coin then falls past the end of the lever 25 into the pocket defined between the gates 35 and 31; whereby the coin at this time may be either.collected or refunded as explained more fully hereinafter. r

When the person at the calling paystation I0 then dials the directory number 800 of the called ordinary subscriber substation I20, the selector of the link we responds to the first digit 8 and the connector 200 may be again selected thereby, and then responds to the second and third digits 0 and 0 to select the subscriber line I20 extending to the called ordinary subscriber substation I20.

First assuming that the called ordinary subscriber substation I20 is busy at this time, when it is tested as such by the connector 200, busy tone current is returned over the loop circuit back to the calling paystation I0 indicating the circumstance noted to the person thereat. When the person at the calling paystation I0 then disconnects by replacing the receiver 83. upon the associated switchhook I1, the switchhook I? is pivoted. in the counterclockwise direction about the mounting block I8 in order to depress the push rod I9 and to open the contacts 29. As the pushrod I9 is depressed, thelug 20 carried thereby engages the horizontal arm of the bell-crank 23 rotating the bell-crank 23 in the clockwise direction; whereby the rod 24 is moved toward the left forcing the end of the associated switch spring over the end of the latch 28 carried on the lever 25 thereby to open the contacts 83. Also as the lever I9 is depressed, the lower end thereof re-engages the horizontal arm of the bell-crank 3I rotating'it in the clockwise direction in order to slide the rod 32 toward the left against the bias of the coil spring 33; wherebythe arm 36 is rotated in the counterclockwise direction opening the gate in the refund chute M in order to cause the deposited coin to fall into the refund receptacle, not shown. At this time the first path including the contacts 29 and the asymmetrical current conducting device 80 and the second path including the contacts 88 and 29 and the asymmetrical current conducting device 0| are both opened; whereby the connector 200 and the link I80 are released; all in the manner previously described.

New assuming that when the connector 200 opcrates to select the subscriber line I2I extending to the called ordinary subscriber substation I20 that the subscriber line I2I is tested as idle, the connector 200 operates to project ringing, current over the subscriber line I2I and to return ring.- back tone current over the loop circuit extending back to the calling paystation I0 in the manner previously explained. Subsequently, when the subscriber at the called ordinary subscriber substation I20 answers the call, the ring cut-off relayR250 and then the back-bridge relay R229 in the connector 200 are operated; whereby the back-bridge relay R220 reverses, at the contacts 22L 222, 223, and 224, the polarity of the trunk I0 and consequently the polarity of the telephone line vI included in the loop circuit extending back to the calling paystation I0. At this time the line conductors CIOI and CI02 of the telephone line I00 are respectively poled positive and negative; whereby the asymmetrical current conducting device 8| passes current via ,the secondpat-h between the line conductors CIOI and CI02; and in an obvious manner the asymmetric current conducting-device blocks the passageof current through the first path between the line conductors CIOI and CI02. Accordinge ly, at this time,the line relay R230 in the connector 2 00 is retained in its operated position retaining operated the connector 200 and the link its; whereby the loop circuit extending from the calling paystation I0 to the upper and lower winding of the line relay R2 30 is operatively connected ,to the loop circuit extending from the called ordinary subscriber substation I20 to the upper and lower windings of the back-bridge relay R220 via the condensers 225 and 226. Accordingly, at this time, an established connection is completed between the calling paystation. I0

\ phonelinel00 that is completed at the calling paystation I0 includes the asymmetrical current conducting device 8|, the winding of the collect relay R90, the contacts 88 and 29, the transmitter 82, the receiver 83 and the contacts 52; whereby the collect relay R operates attracting the arm 38 rotating the gate 31 to its open position in the collect chute I3. Accordingly, the coin in the pocket defined by the gate 35 and 3'! fallsthrough the collect chute I3 into the collect box, not shown.

Subsequently, when the person at the calling paystation I0 disconnects by returning the receiver 83 upon the associated switchhook H, the push rod I9 is depressed in order to bring about opening of the contacts 88 and opening of the gate 35 in the refund chute I4. Also the contacts 29 are opened by the switchhook H; whereby the connector- 200 and the link I80 are releasedin the manner previously explained. Also when the contacts 88 arepopened, the circuit for energizing the winding of the collect relay R90 is interrupted; whereby the arm 30 is released causingv the gate 37 again to close the collect chute l3. At this time the connection between the calling paystation l and the called ordinary subscribersubstation I is released and all of the apparatus involved therein is completely released and available for further use.

Now assuming that a call is to be extended from the calling paystation I0 to the operator position I40, the person at the paystation I0 initiates the call by removing the receiver 83 tending to the calling paystation I I) and dial tone current in theselector of the link I80 is returned over the loop circuit back to the calling paystation I0. V 7

When the person at the calling paystation I0 dials the single digit 0, the selector of the link I80 responds thereto in order to select the group of trunks, including the trunk I41, and then an idle trunk'in the group mentioned. For example, the selector of the link 180 may select the trunk I4Iterminated bythe trunk circuit I 42 and extending to the operator position I40,

the trunk I4I being marked as idle by the associated trunk circuit I42. When the selector of the link I80 selects the trunk I4I, it switches through, completing a direct loop circuit between the calling paystation I0 and the line relayynot shown, in the trunk circuit I42; whereby the linev relay mentioned operates to effect signalling over the trunk I 4| indicating to the, operator at the position I40 that a call iswaiting to be answered on the trunk I4I. When the operator at the position I40 answers the call, the trunk circuit 142 operates to completea. connection between the calling paysta- 7 tion I0 and. the called operator position I40. Of course, when the trunk circuit I42 switches through, the polarity of the loop circuit extending back to the calling paystation I0 is not reversed'as his not desired to block the transmitter 8.2 and the receiver 83 thereatand'. to

effect the, release or the connection since. the present connection represents a free call aspreviously explained. At the conclusion of; the established connection, when the person at the calling paystation l0 disconnects by replacing the receiver 83 upon the. associated switchhook I I, the loop circuit extending therefrom to. the.

erates to mark the telephone line I00 as idle to the connectors 200, etc., having access thereto.

At this time the established connection between the calling paystation I0 and the called operator= position I 40 is released and all of the apparatus. involved therein is completely released and available for further use.

' Now: assuming that a call is to be extended from the calling paystation I0 to a called suburban subscriber substation in another exchange, not shown, the person at the paystation I0'initiates the call by removing thereceiver 83 from the switchhook Il'; whereby the.

line circuit, II 0 is again controlled'to govern operation of the distributor whereby the link I may be again assigned for use. The finder of the link again operates to 'find the telephone line I00 extending to the calling paystation I0; whereby dial tone current in the selector'of the'link I80 is returned over the loop circuit to the calling paystation 10; all in the manner previously explained. In order to complete a connection from the calling paystation I0 to the called suburban subscriber substation mentioned, it is'necessary for the person at the V calling paystation I0 to deposit a coin in the suburban call chute I2, as well as to dial the directorynumber of the called suburban subscriber substation mentioned, which directory number is preceded by the prefix digit 11 and maybe 11-4234. However, the person at the calling paystation It may attempt the extension of" the connection in an unauthorized manner to the called suburban subscriber substation mentioned without depositing the coin in the suburban call chute I2 merely by dialing the directory number 11 -1234 of the called suburban subscriber substation mentioned; whereupon the call is intercepted at the operator position I40 in the exchange illustrated'as explained more fullybelow.

First assuming that the person at the calling paystation I0 attempts the extension of the connection therefrom to the called suburban subscriber substation mentioned in anunauthorized manner by' failing to deposit a coin in the suburban-call chute I2, and merely by dialing the directory number 11-1234; When the finger wheel of the dial I5 at the calling paystation I0 is operated in accordance with the digit 11, the impulsecontacts 10 are controlled to transmit in a single series, eleven impulses; however, the cam 18 is arranged to close the shunt springs 11 dur ing the transmission of the eleventh impulse of the series mentioned; which circumstance causes the dial [5 to transmit only a series of ten impulses over the telephone line I00 unless the contacts 30 are also opened; which operation is brought about only incident to the depositing of a coin in the suburbancall chute I2 as explained more fully below. Accordingly, in the present example, the contacts 30 are closed; whereby-the cam Iii closes the shunt springs 11 during the transmission of the eleventh impulse by' the impulse contacts 15; whereby a shunt path is completed via the contacts 30 and the shunt springs" 17 around the impulse contacts I6 of the" dial "I5". Hence, the dial I5 transmits the digit 0 even. though the finger wheel thereof was operated in accordance with, theudigit 11 due to V the circumstance above noted; whereby the selector of the link. I80 receives the digit 0 and opcrates in the manner previously explained first to select the group of trunks, including the trunk MI, and then an idle trunk in the group mentioned. Accordingly, the connection may be routed from the calling paystation I0 by the selector of the link I 80 over the trunk I4I to the operator position I40, the trunk I4I being marked as idle to theselector'of the link, I80 by the-trunk circuit l42. The remaining digits 1234 dialed at the calling paystation I0 are without eflect as they are merely transmitted to the line relayin the'trunk circuit I42. When the operator' at the position I 40 answers the call, the trunk circuit I42 operates to complete a connection between the calling paystation I and the called operator position "I40; however, the polarity of the loop circuit extending back to the calling paystation I0 is not reversed as it is not desired to block the transmitter 82 and the receiver 83 thereat and to effect the release of the connection since the present connection represents a free intercepted call. The operator at the position I40 advises the person at the calling paystation I0 that the call has been intercepted by virtue of the fact that he attempted the extension of a connection to a called suburban subscriber substation in an unauthorized manner without depositing a coin in the suburban call chute I2. At the conclusion of the established connection, when the person at the calling paystation I0 disconnects and the operator at the position I40 disconnects, the apparatus is released in the manner previously described.

Now assuming that the person atthe calling paystation I0 after initiating the call by removing the receiver 83 from the associated switchhook II first deposits a coin in the suburban call chute I2 before dialing the directory number 11-1234 of the called suburban subscriber substation mentioned. When the coin is deposited in the local call chute I2, it falls past the end of the push rod 28 urging it toward the right; whereby the contacts are opened and the end of the associated switch spring is caught behind the latch 22 carried by the lever 2I pivotally mounted both to the push rod I9 and to 88 and 29, the transmitter 82, the receiver 83 v and the contacts 52 is completed between the line conductors CIOI and CI02 of the telephone line I00.

At this time when the person at the calling paystation I0 dials the digit 11 the impulse contacts I6 transmit a series of eleven impulses and the cam 18 closes the shunt springs I1 during the transmission of .the eleventh impulse of the series; however, without effect, since the contacts 30 occupytheir open position. Accordingly, in the present example a continuous series of eleven impulses is transmitted'over the telephone line I00 in accordance with the digit ll dialed by the person at the calling paystation I0. The selector of the link I80 responds to the digit 11 to select the group of suburban selectors, including the suburban selector I50, and then an idle suburban selector in the group mentioned. For

example, the selector of the link I80 may select the trunk I5I extending to the suburban selector I; whereupon the selector of the link I80 switches through. The suburban selector I50 then responds to the second digit 1 dialed at the calling paystation I0 to select the corresponding group of trunk lines and then an idle trunk line therein extending to the corresponding suburban exchange and then switches through. The automatic switching apparatus, not shown, in the 14 suburban exchange mentioned responds to the remaining digits 2, 3 and 4 to select the subscriber line extending to the called suburban subscriber substation mentioned. The subsequent operaswitching apparatus mentioned operates to in-.

terrupt the projection of ringing current over the subscriber line extending to the called suburban subscriber substation, to interrupt the return of ring-back tone current over the connection extending back to the calling paystation I 0, and to reverse the polarity of the loop circuit extending back to the calling paystation). When the polarity of the loop circuit extending back to the calling paystation I0 is reversed, the asymmetrical current conducting device blocks the passage of current through the first multiple path, while the asymmetrical current conducting device 8I passes current through the second multiple path operating the collect relay R90. The collect relay R attracts the arm 38 rotating the gate 31 to its open position in the collect chute I3. Accordingly, the coin in the pocket defined by the gates 35 and 3'! falls through the collect chute I3 into the collect box, not shown. At this time an established connection is completed between the calling paystation I0 and the called suburban subscriber substation mentioned.

Subsequently, when the-person at the calling paystation I0 disconnects by returning the receiver 83 upon the associated switchhook II, the push rod i9 is depressed in order to bring about opening of the contacts '88 and opening of the gate 35 in the refund chute I4. Also the contacts 29 are opened by the switchhook I'I; whereby the automatic switching apparatus, not shown, in the suburban exchange mentioned, the suburban selector I50 and the link I80 are released in a manner identical to that previously explained. Also when the contacts 88 are opened, the circuit for energiz-- ing the winding of the collect relay R90 is interrupted; whereby the arm 38 is released causing the gate 31 again to close the collect chute I3. Further when the push rod? I9 is depressed, the lever 2| is rotated inthe'counterclockwise direction about the mounting block I8 causing the latch 22 to disengage the associated. spring; whereby the contacts 30 are again closed in order to render efiective the shunt springs 11 controlled by the cam 18 in the dial I5. At this time the connection between the calling paystation I 0 and the called suburban subscriber substation-mentioned is released and all of theapparatus involved therein is completely released and available for further use.

Now assuming that a call is to be extended from the calling ordinary subscriber substation I20 to the called paystation I0, the subscriber at the calling ordinary subscriber substation I20 first initiates the call and then dials the directory number of the called paystation H], which directory number may be 811. When the call is initiated at the calling ordinary subscriber subi5 station I20, theilinecircuit. I22 is controlled over the associated'subscriber' lineil2l and operates to apply ground-1 potential to thedistributor start conductorCIZii; whereby thedistributor ilt is governed to assign an idle one of the links, such for example, asthe link I88, The finder of the link. IEO operates to find the subscriber line iZI extendingto' the calling ordinary subscriber substation I20; whereby the line circuit 22 is operated. to mark the subscriber line iZI as busy to the connectorsr200; etc., having accessthereto. When the first digit 8 is dialed at the calling ordinary subscriber substation I28, .the selector of the link I80 responds thereto to select the group of connectors; including the connector 200, and then an idle connector in the group mentioned. For example, the finder of the link lull may select the trunk 2H5 extending to the connector 2530'; whereby the selector of the link, I83 switchesthrough completing a loop circuit between the calling ordinarysubscriber substation 12 and the line relay R230 in the connector 223.

'When the second and third digits landl are dialed at the calling'ordinary subscriber substation I28, the line-- relay R230 in the connector 2&0 follows bringing about operation of the Strowger mechanism 278 to select the telephone line I extending to the called paystation It.

, The idle or busy condition of the called paystation it is then tested by-the test relay, not shown, in the connect-011.2911, ground potential being applied to the control, conductor 0503 of the telephone. line in the event the called paystation I!) is busy at this; time and battery potential in the line circuit IIO being applied to the control conductor CI03 of the telephone line I98 in the event the called paystation I0 isidle at this time. The connector 200 operates in response tothe markingsmentioned in the manner previously explained; and'assuming that thepaystation I0 is idle, at this time, the test relay, not shown, in the connector 280 does not operate and the switch relay, not shown, in the connector 2% operates to connect ringing current. over a path,no't shown, including the ringing conductor C258, the upper winding of the ring cut-0E relay R259, the contacts 251 and 26I to the line conductor CIOI of the telephone line I90; the line conductor CI02 of the telephone line I00 being connected via the contacts 263 and 254 to Also ring-back tone current is returned via .a connection, not shown, over the ground potential.

loop circuit extending back tothe calling ordinary subscriber substation I20 in order to indicats to the subscriber. thereat that the called paystation I0 is: being signalled atthis time. The ringing current projected over thelineconductors' CHM and C522- of the telephone line It!) trav erses a path, including the winding ofthe alter.- nating current lockrelay' R50, the glow tube 81, the ringer 86 and the condenser 85; whereby the glow tube 8'! is rendered conductive, the lock.

relay R50 is operated, and the ringer 8B is operated in order to signal the called paystation t is caught behind theinsulating latch 42 carried by the switch spring 4| in order to retain .the contacts 52 in their open circuit position andto retain the contacts 5| in their closed circuit po= sition. At this time the line conductors CIOI and CI02 of the telephone line I 80 'arerespectively poled negative. and positive; whereby the asymmetrical current conducting device BIfblocks the passage of current through the winding of the unlock relayR60, thereby preventingenergization of. the upper winding of the ring cut-ofi relay R250 in the connector 290 and the consequent operation thereof at this time. Accordingly; the projection of ringing current from the connector 260. over the telephone line N to the the contacts 233 a circuit, including the contacts 224i and 255, for energizing the winding of the unlock relay R260; whereby the latter relay opcrates shortly thereafter, it being of the slow temperate type. Upon operating the unlock relay RZtG interrupts, at the contacts 26! and 7 contacts 262 and 264 paths for connecting ground 263, the path for projecting ringing currentoyer the telephone line) Hi0; and completes, at the potential and battery potential via the resistor 25? respectively to the line conductors CIIH and C102 of the telephone line 520. At this time the line conductors CI'DI and CI02 of the telephone line 1'00 are poled respectively positive and nega' tive; whereby the'asyinmetri'cal current, conduct ingdevice 8| passes current through the winding of the unlock relay R60 at the called paysta tion I0 effecting operation thereof. -Upon oper} ating the unlock relay R68 moves the switch spring 4| downwardly closing the contacts GI, without effect at this time, whereby the insulating latch 42 disengages the associated switch or spring causing the switch spring mentioned to be restored in order to open the contacts 5| and to close the contacts 52. When the contacts 5| are thus opened, the circuit for operating the urn lockrelay" R60 'is interrupted; and when the contacts- 52 are closed, the circuit 'for connecting the transmitter 82 and the receiver 83 across the line conductors CIOI. and C102 of the telephone line itilis prepared. The unlock relay R60 then restores whereby the switch spring M a is restored in the upper. direction and the contacts GI are opened. At this time theapparatus at the called paystation It is completely released.

' Shortly following the ;restoration of the line relay R230-in .the connector 200, the hold relay R240, being of the slow-to-release type, restores to interrupt at the contacts 24I, the circuit for retainingoperated the unlock relay R260 and to bring about the release of the Strowger mechanism 218 and the remainder of the operated relays in the connector 200; whereby the link I-8Ii is released. At this time theline circuit E22 operates in order toreturn battery potential upon thecontrol conductor of the subscriber line I21; whereby the subscriber line .I 2| is marked as idle to theconnectors 200,.etc., having access time asserts to. At this time all of the operated apparatus has been completely released.

Now assume that when the call is extended in the manner described above from the calling ordinary subscriber substation I20 to the called paystation 50, a person at the called paystation I answers the call. In order to answer the call the person at the called paystation I0 must not only remove the receiver 83 from the associated switchhook Il, but he must deposit a coin in the answer chute I5. More particularly, when the receiver 03 is removed from the associated switchhook H, the contacts 29 are closedj however, the circuit for connecting the transmitter 82 and the receiver 83 across the line conductors C IOI and CI02 of the telephone line I00 remains open at the contacts 52, since the insulation latch 42 retains the contacts 52 in their open position and the contacts i in their closed position as previously explained. Thus no communication connection is completed at the called paystation I0 merely by removing the receiver 83 from the associated switchhook ll. However, when the person at the called paystation I0 deposits. a coin in the answer chute I5, the coin falls past the end of the switch spring 4| depressing the switch spring 4| closing the contacts BI to complete a direct short across the line conductors CIOI and CI02 of the telephone line I 00 and to cause the insulation latch 02 to disengage the associated spring; whereby the contacts 5I are opened and the contacts 52 are closed. The coin mentioned then falls into the collect box, not shown. When the direct short mentioned is completed between the line conductors C IOI and CI02 of the telephone line I00, a circuit substantially identical to that previously traced is completed for energizing. the upper winding of the ring cut-01f relay R25 0 in the connector 200. The ring cut-off relay R250 then operates to complete a holding circuit, not shown, for energizing the lower winding thereof; to interrupt, at the contacts 25I and 254 the path for projecting ringing current over the telephone line I00; and to complete at the contacts 252 and 253, a loop circuit between the upper and lower windings of the back-bridge relay R220 and the called paystation I0. The loop circuit mentioned includes the contacts 252, 253, 26I and 203, the line conductors CHM and CI02 of the telephone line I00, the impulse contacts 16 of the dial I5, the asymmetrical current conducting device 80, the contacts 29, the transmitter 82, the receiver 83, and the contacts 52. Since the line conductors CIOI and CI02 are poled respectively negative and positive currents traverse the loop circuit traced above via the asymmetrical current conducting device 80 energizing the transmitter 82 and the receiver 83 as well as the upper and lower windings of the back-bridge relay R220. Accordingly, the back-bridge relay R220 operates in order to reverse at the contacts 22I, 222,- 223 and 224, the polarity of the loop circuit extending between the calling ordinary subscriber substation I20 and the upper and lower windings of the line relay R230; which reversal of polarity over the loop circuit mentioned may be employed in the line circuit I22 individually associated with the subscriber line I2I for metering or other control purposes in a conventional manner. Finally,- the loop circuit extending between the calling-oh dinary subscriber substation I20 and the line relay R230 and the loop circuit extending between the called paystation I 0 and the back-bridge re lay R220 are interconnected by the condensers 225 and 226 completing an established connection between the calling ordinary subscriber substation I20 and the called paystation I0. H

' At the conclusion of the established connection when the subscriber at the calling ordinary subscriber substation I20 disconnects, the line relay R230 restores in order to bring about the restoration of the hold relay R240 shortly thereafter the latter relay being of the slow-to-release type. In this case the unlock relay R260 is not operated incident to the restoration of the line relay R230 since the ring cut-off relay R250 occupies its operated position interrupting, at the contacts 255, a point in the previously traced circuit for operating the unlock relay R260. Accordingly, the connector 200 is released bringing about the release of the link I; whereby the line circuit I22 operates again to mark the subscriber line I2I as idle to the connectors 200, etc., having access thereto. Also whenthe connector 200 is thus released, ground potential is removed from the control conductor CI03 of the subscriber line I00; whereby the line circuit II 0 operates in order again to mark the telephone line I00 as idle to the connectors 200, etc., having access thereto, assuming that the person at the called paystation I0 has disconnected at this time. When the person at the called paystation I0 disconnects by replacing the receiver upon the switchhook I! the contacts 29 are opened disconnecting the transmitter 82 and the receiver 83 from across the line conductors CIOI and CI02 of the telephone line I00. At this time the connection between the calling ordinary subscriber substation I20 and the called paystation I0 is released and all of the apparatus involved therein is completely released and available for further use.

In view of the foregoing it will be understood that in order to answer a call in the called paystation I0, it is necessary to deposit a coin in the answer chute I 5 in order to effect the release of the insulation latch 42 and closure of the contacts 6 I in the manner previously explained. However, an alternative arrangement is provided for accomplishing these objectives that comprises the push button I0, the meter 41 and the lock mechanism L90. More particularly, an authorized person at the called paystation possess a key which will fit the lock mechanism L; whereby the latch 9I may be retracted from below the associated lug 92 carried by the push button 10; whereby the push button 10 may be depressed manually. When the push button I0 is thus operated the finger II carried thereby engages and depresses the switch spring 44 in a manner identical to the action of a coin deposited in the answer chute [5; whereby the insulation latch 62 releases the associated switch spring and the contacts 8| are closed for the purpose previously explained. Also when the push rod 10 is thus operated the lower end thereof engages the pivotally mountedlever 44 depressing it causing the pall $5 to operate the associated ratchet t6; whereby the wheels of the meter are actuated to register one call.

In view of the foregoing, it will be understood that a call may be answered at the called paystation I0 either by depositing a coin in the answer chute I5 or by depressing the push rod I0 after the lock mechanism L90 has been operated. In the first'mentioned event, the coin deposited in the answer chute I5 falls into the collectbox, not shown; and in the second mentioned event the meter 47 is operated toregister the answering of acall at the'called paystation I0. Thus the coin controlled mechanism, in-

I0 may cluding the answer chute i5, constitutes a first 'manually' controlled incoming call register; and

the key-lock controlled mechanism, including the push button ID, the lock mechanism L9!) and the 'meter 41,- constitutes 'a second manually controlled incoming call register. It, of course, follows that in order to totalize the incoming calls to the paystation 10 registered during a given period that it is necessary both to count the coins in the collect box, not shown, associated with the answer chute l5, and to read the meter 41. Likewise it will be understood that the coin controlled mechanism, including the local call chute I I, the suburban call chute i2 and the collect chute l3, constitutes a manually controlled outgoing call register; and that in order to totalize'the' outgoing callsfrom the paystation ii) registered during a given period it is necessary only to count the coins in the collect box, not

shown, associated with the collect chute l3. More particularly, the numberof small denomination coins in the collect box mentioned corresponds to the number of local outgoing calls that has been completed from the paystation I0; and the number of high denomination coins in the collect box mentioned corresponds to the number of suburban outgoing calls that has been completed from the paystation l0.

Finally, in connection with the arrangement of the equipment at the paystation it, it is noted 7 that at the end of a given period should the total number of outgoing calls registered bear a reasonable relationship with respect to the total number of incoming calls registered, the person on whose premises the paystation I0 is located may be entitled to an appropriate refund of at calls completed therefrom and the number of incoming calls completed thereto.

. In view of the foregoing it is apparent that I there has been provided an automatic telephone system including a paystation circuit incorporating an improved coin controlled arrangement for 1 governing, both the extension of outgoing calls therefrom and the answering of incoming calls thereto.

While there, has been described what is at present considered to be the preferred embodi- V ment of the invention, it will be understood that various modifications may be made therein, and it is intended to cover in the appended claims all such modifications as fall within the true spirit and scope of the invention. V 7 What is claimed is: i

1. In an automatic telephone system including a calling station, a called station, a calledoperator position, and numerical switching apparatus accessible to said calling station and having access to said called station and to said called operator position, said switching apparatus being responsive to a first digit to route the calLtoward said called station and to a second digit to route the call toward said called operator position, wherein said first digit is larger than said second digit; digit mechanism located at said calling station and selectively operative to register said first digit or said second digit and to transmit the. registered at said calling station for transmitting from said calling station to said switching apparatus said second digit in response to the transmission of said first digit by said digit mechanism in order that the call from said calling station is routed by said switching apparatus toward said called operator position instead of toward said called station as intended, and manually controlled call registering mechanism located at said calling station for rendering ineffective said blocking means so that said first digit is transmitted from said calling station to said switching apparatus in response to the transmission of said first digit by said digit mechanism in order that the call from said calling station is routed by said switching apparatus toward said called station as intended.

'2. In an automatic telephone system includin a calling station, a called station, a called operator position, and numerical switching apparatus accessible to said calling station and having access to said called station and to said called operator position, said switching apparatus being responsive to a first digit to route the call toward said called station and to a second digit to route the call toward said called operator position, wherein said first digit is larger than said second digit; digit mechanism located at said calling station and selectively operative to register said first digit or said second digit and to transmit the registered digit, normally effective blocking means located at said calling station for transmitting from said calling station to said switching apparatus said second digit in response to the transmission of said first digit by said digit mechanism in order that the call from said calling station is routed by said switching apparatus toward said called operator position instead of toward said called station as intended, and coin-controlled call registering mechanism located at said calling station for rendering ineffective said blocking means so that said first digit is transmitted from said calling station to said switching apparatus in response to the transmission of said first digit by said digit mechanism in order that the call from said calling station is routed by said switching apparatus toward said called station as intended.

3. In an automatic telephone system including a calling station, a called station, a called operator position, and numerical switching apparatus accessible to said calling station and having access to said called station and to said called operator position, said switching apparatus being responsive to a first digit to route the call toward said called station and to a second digit to route the call toward said called operator position, wherein said first digit is larger than said second digit; digit mechanism located at said calling station and'including means selectively operative to register said first digit or said second digit and impulse contacts operative to transmit the registered digit and auxiliary contacts closed in response to operation of said impulse contacts to transmit said second digit, means including normally closed blocking contacts located at said calling station and connecting said auxiliary contacts in shunt to said impulse contacts for caus ing the transmission from said calling station to said switching apparatus of said second digit in response to the transmission of said first digit by said impulse contacts in order that the call from said calling station is routed by said switching-apparatus toward said called operator posi- 21 tion. instead of toward said called station as intended, and manually controlled call registers .ing mechanism located at said calling station tor opening said blocking contacts so that said first digit is transmittedfrom said calling station to said switching apparatus in response to the transmission of said first digit by said impulse contacts in order that the call fromsaid calling station is routed by said switching apparatus toward said called station as intended.

i. In a telephone system including a line, ,a station associated with said line, and means for extending outgoing calls from said station over saidline and for routing incoming; calls to. said station over said line; said station comprising first and second coin-operated mechanisms, normally eifective first blocking means. for preventing the completion of a, two-way communication connection incident to initiation of an outgoing call from said station, means controlled by operation of said first mechanism for disabling said first blocking means, normally effective second blocking means for preventing the completion of a two-way communication connection incident to answering of an incomin call to said station, and means controlled by operation of said second mechanism for disabling said second blocking means.

5. In a telephone system including a line, a

station'associated with said line, and means for f routing a call over said line to said station; said station comprising coin-operated mechanism, normally eil'ective blocking means for preventing the completion of a two-way communicationconnection incident to answering of a call to said station, and means controlled by operation of said mechanism for disabling said blocking means. 7

6. In a telephone system, including a line, a station associated with said line, and means for routing a call and. for projecting signal current over said line to said station; said station comprising a signal operated by the projection of signal current over said line, a device normally able to answer a call on said line, blocking means rendered eifective in response to the projection of signal current over said line for disabling said device, and manually controlled means for rendering ineffective said blocking means, whereby said device is again enabled.

7. In a telephone system including a line, a station associated with said line, and means for routing a call and for projecting signal current over said line to said station; said station comprising a signal operated by the projection of signal current over said line, a device normally able to answer a call on said line, blocking means rendered effective in response to the projection of signal current over said line for disabling. said device, and manually controlled means for arresting the projection of signal current over said line and for rendering ineffective said blocking means, whereby said device is again enabled.

8. In a telephone system including a line, a station associated with said line, and means for routing a call and for projecting signal current over said line to said station; said station com prising a signal operated by the projection of signal current over said line, a device normally able to answer a call on said line, blocking means rendered effective in response to the projection of signal current over said line for disabling said device, and manually controlled call registering mechanism for rendering inefiective said blocking means, whereby said device is again enabled.

9-.Inaetelephonevsystem; including a line, a

station associated with, said line, and means for routing a call and for projecting, signal current ovens-aid line to said station; said station comprising .a signal operatedjbythe projection of signal current over said line, a device normally able to answer a call on saidline, blocking means rendered effective inresponse to the projection of signal current oversaid line for disabling said device, and coin controllel registering mechanism for rendering inefiective said blocking. means, whereby said device is again enabled.

it. In a telephone system including, a line, a station associated with said line, and means: for routing ,a call and, for projecting, signal. current over said line to said station; said station comprising a; signal. operated by the projection of signalcurrent over said line, a. device normally able to answer a call on said line, blockingmeans rendered eiifective in response to the. projection of signal current over said line for disabling said device, and key-lock controlled call registering mechanism for rendering ineffective said block ing means, whereby said device is again enabled.

1-1. In a telephone system. including a line, a

station associated with, said line, and means for routing a call and for projecting signal current over said line to said station; said station. comprising a transmitter-receiver circuit, a hook.- switch normally operative to connect said circuit to said line, a signal deviceand a relay both operated by the projection of signal current over said line, blocking means rendered effective in,

response to operation of said relay for rendering said hook-switch inoperative to connectsaid .prising a transmitter-receiver circuit, a hookswitch normallyoperative to connectsaid circuit to said line, a signal device and a relay both operated by the projection of signal current over said line, blocking means rendered effective in response to operation of said relay for rendering said hook-switch inoperative to connect said cir-- cuitto said line, and manually controlled call registering mechanism for rendering ineffective said blocking means, whereby said hook-switch is 2 again rendered operativelto connect said circuit to said line.

13. In a telephone system including a line, a station associated with said line, and means for routing a call and for projecting signal current over said line to said station, said station comprising a transmitter-receiver circuit, a hookswitchnormally operative to connect said circuit to said line, a signal. device, and a relay both operated by the projection of signal current over said line, blocking means rendered efiective in response to operation of said relay for rendering said hook-switch inoperative to connect said circuit to said line, and coin controlled call registering mechanism for rendering inefiective said blocking means, whereby said hook-switch is again rendered operative to connect said circuit to said line.

14. In a telephone system including a line, a station associated with said line, and means for routing a call and for projecting signal current over said line to said station, said stationcomprising a transmitter-receiver circuit, a hookswitch normally operative to connect said circuit to said line, a signal device and a relay both operated by the projection of signal current over said line, blocking means rendered effective in response to operation of said relay for rendering said hook-switch inoperative to connect said circuit to said line, and key-lock controlled call registering mechanism for rendering ineffective said blocking means, whereby said hook-switch is again rendered operative toconnect said circuit to said line. r

15. In a telephone system including a line, a station associated with said line, and means for routing a call and for projecting signal current over said line to said station; said station comprising a transmitter-receiver circuit, a path including a hook-switch; and a pair of normally closed contacts for connecting said circuit to said line, whereby said hook-switch is normally operative to complete said path, a signal and a relay both operated by the projection of signal current over said line, means responsive to operation of said relay for opening said pair of contacts, whereby said hook-switch is rendered inoperative to complete said path, and manually controlled means for reclosing said pair of contacts, whereby said hook-switch is again rendered oper ative to complete said path.

16. In a telephone system including a line, a station associated with said line, and means for routing a call and for projecting signal current over said line to said station; said station comprising a transmitter-receiver circuit, a path including a hook-switch and a pair of normally closed contacts for connecting said circuit to said line, whereby said hook-switch is normally operative to complete said path, a signal and a relay both operated by the projection of signal current over said line, means responsive to operation of said relay for opening said pair of contacts, means for latching in open position said pair of contacts, whereby said hook-switch is rendered inoperative to complete said path, and manually controlled means for releasing said latching means, whereby said pair of contacts is reclosed in order again to. render said hook-switch operative to complete said path.

17. In a telephone system including a line, a station associated with said line, and automatic switching apparatus; said switching apparatus comprising a switching mechanism having access to said line, means for operating said switching mechanism to select said line, means controlled by operation of said switching mechanism to select said line for routing a call and for projecting signal current thereover to said station, means responsive to answering of the call at said station for arresting the projection of signal current over said line, and means responsive to abandoning of the call prior to answering thereof at said station for arresting the projection of signal current over said line and for projecting a splash of unblock signal over said line and then for releasing said switching mechanism; said station comprising a signal operated by the projection ofsignal current over said line, a device normally able to answer a call on said line, blocking means rendered effective in response to the projection of signal current over said line for disabling said'device, manually controlled means for rendering ineffective said blocking means, whereby said device is again enabled, and additional means responsive'tothe projection of a splash of unblock signal over said line for rendering inefiective said blocking meanswhereby said device is again enabled;

18. In a telephone system including a line, a station associated'withsaid line, and automatic switching apparatus; said switching apparatus comprising a switching mechanism havingaccess to said line, rneans for operating said switching mechanism to select said line, means controlled by operation of said switching mechanism to select said line for routing, a call thereover and for projecting signal current thereover to said station, means responsive to answering of the call at said station for arresting the projection of signal current oversaid line, and means responsive to abandoning of the call prior to answering thereof at said station for arresting the projection of signal current over said line and for projecting a splash of unblock signal over said line and then for releasing said switching mechanism; said station comprisinga signal and a block relay both operated by the projection of signal current over said line, a device normally able to answer a call on said line, blocking means rendered efiective in response to operation of said block relay for disabling said device, manually controlled means for rendering ineffective said 40 blocking means, whereby said device is again enabled, an unblock relay operated by the projection of unblock current over said line, and means responsive to operation of said unblock relay for rendering ineffective said blocking means, whereby said device is again enabled.

CLARENCE E. LOMAX. JOHN M. WILD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Molnar 1 Sept. 25, 1945 

